Fix:/Number of count of major element in Boyer Moore algorithm (#4728)

* Number of count of major element in Boyer Moore algorithm

* test: add `BoyerMooreTest`

* style: basic linting

* tests: add test case from the issue

---------

Co-authored-by: Piotr Idzik <65706193+vil02@users.noreply.github.com>
Co-authored-by: vil02 <vil02@o2.pl>
This commit is contained in:
Satvik Singh Sengar 2023-10-30 22:54:23 +05:30 committed by GitHub
parent 9dde8a7808
commit 945e7b56bb
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2 changed files with 32 additions and 20 deletions

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@ -6,27 +6,28 @@ https://en.wikipedia.org/wiki/Boyer%E2%80%93Moore_majority_vote_algorithm
*/
package com.thealgorithms.others;
import java.util.*;
public final class BoyerMoore {
private BoyerMoore() {
}
public class BoyerMoore {
public static int findmajor(int[] a) {
public static int findmajor(final int[] a) {
int count = 0;
int cand = -1;
for (int i = 0; i < a.length; i++) {
for (final var k : a) {
if (count == 0) {
cand = a[i];
cand = k;
count = 1;
} else {
if (a[i] == cand) {
if (k == cand) {
count++;
} else {
count--;
}
}
}
for (int i = 0; i < a.length; i++) {
if (a[i] == cand) {
count = 0;
for (final var j : a) {
if (j == cand) {
count++;
}
}
@ -35,15 +36,4 @@ public class BoyerMoore {
}
return -1;
}
public static void main(String[] args) {
Scanner input = new Scanner(System.in);
int n = input.nextInt();
int[] a = new int[n];
for (int i = 0; i < n; i++) {
a[i] = input.nextInt();
}
System.out.println("the majority element is " + findmajor(a));
input.close();
}
}

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@ -0,0 +1,22 @@
package com.thealgorithms.others;
import static org.junit.jupiter.api.Assertions.assertThrows;
import java.util.stream.Stream;
import org.junit.jupiter.api.Assertions;
import org.junit.jupiter.api.Test;
import org.junit.jupiter.params.ParameterizedTest;
import org.junit.jupiter.params.provider.Arguments;
import org.junit.jupiter.params.provider.MethodSource;
public class BoyerMooreTest {
@ParameterizedTest
@MethodSource("inputStream")
void numberTests(int expected, int[] input) {
Assertions.assertEquals(expected, BoyerMoore.findmajor(input));
}
private static Stream<Arguments> inputStream() {
return Stream.of(Arguments.of(5, new int[] {5, 5, 5, 2}), Arguments.of(10, new int[] {10, 10, 20}), Arguments.of(10, new int[] {10, 20, 10}), Arguments.of(10, new int[] {20, 10, 10}), Arguments.of(-1, new int[] {10, 10, 20, 20, 30, 30}), Arguments.of(4, new int[] {1, 4, 2, 4, 4, 5, 4}));
}
}